Fuel for internal combustion engines



Patented Nov. 27, 1934 PATENT OFFICE FUEL FOR INTERNAL QOMBUSTIO ENGINESJean Felix-Paul cle La Riboisiere, Paris, France No Drawing. ApplicationNovember 16, 1931, Serial No. 575,474. In Great Britain December 6Claims.

This invention relates to fuels for internal combustion engines,consisting mainly or essentially of liquid aliphatic or petroleumhydrocarbon material with the addition of a proportion of an aromaticamine, for the purpose of reducing knocking.

The employment of aromatic amines in association with liquid hydrocarbonmaterial for preventing knocking is claimed in the British SpecificationNo. 140,041 and it has been proposed also to introduce anilineinto fuelsof the alcohol ether type.

The observation on which the invention forming the subject-matter ofBritish Letters Patent No. 257,613 is based is that by the addition toliquid hydrocarbons of small proportions of aniline or a correspondingaromatic amine and an alkyl ether or ketone the tendency of thehydrocarbon material to exhibit knocking is con- 'siderably reduced.

The proportion of aniline or a corresponding aromatic amine neededsufficiently to suppress knocking varies in the case of differenthydrocarbon materials and, moreover, the solubility of aniline indifferent hydrocarbon materials varies considerably, aniline beingsubstantially if not completely insoluble in hydrocarbon materials freefrom so-called aromatics, as naphthenes and paraflins are for practicalpurposes non-solvents of aromatic amines. For-instance, it has beenfound that at low temperatures the more readily the aromatic aminesseparate from hydrocarbon material in which they have been dissolved,the lower is the proportion of aromatics present therein. I It isparticularly in connection with fuels containing a relatively lowproportion of aromatic hydrocarbons or free from aromatic hydrocarbonsthat it is necessary to resort to the use of agents adapted to suppressknocking and the proportiorf of such agents required to a large extentwill be conditioned by the content of aromatics in the hydrocarbons.

The employment of small proportions of ether or acetone or like keton inassociation with aromatic amines assists in promoting their solution inhydrocarbon materials but increasein the proportion ofether to securethis end is open to ob jection as 1.180 is an increase in the proportionof ketone us\ i. v

The'use of a wide variety of other solvents for assisting the; solutionof aniline in paraffin hydro carbon in has been suggested but many ofthe proposed i ents are unsuitable for use on a practical s l a onaccount of their high cost, while others, for instance, ethyl and methylalcohol in the form in which they have hitherto been usually availablein commerce are inoperative.

It has now been found that by the employment of relatively smallproportions of ethyl or methyl alcohol in the completely orsubstantially anhydrous state, the solution of a suitable proportion ofaniline or a like aromatic amine or a body isomeric therewith inhydrocarbon materials which are normally non-solvents or poor solventsof such amines may be facilitated.

The invention, therefore, may be stated to consist in a fuel forinternal combustion engines consisting essentially of hydrocarbonmaterial and containing a proportion of an aromatic amine or anazocyclic compound adapted to suppress knocking" in association withsubstantially anhydrous ethyl or methyl alcohol in a proportion which issmall relative to the hydrocarbon material and in the absence of ironcarbonyl or like 5 I metal compounds possessing anti-knock properties.

Generally, it may be stated that the ethyl or methyl alcohol must be of,at least, 99.5 per cent. strength.

Normally in accordance with the invention the substantially anhydrousethyl or methyl alcohol will be present in the fuel in a proportion notconsiderably exceeding the proportion of aromatic amine therein.

Generally, the proportion will not exceed twice the weight of the amineand in practice a ratio of between 1.2 and 1.5 parts by volume per onepart by volume of aromatic amine will be found sufficient.

In this connection it may be remarked that the ratio of substantiallyanhydrous ethyl or methyl alcohol to aromatic amines above referred tomay be increased without exceeding the scope of the invention, but byincreasing the proportion of alcohol the necessity for introducing aproportion of an aromatic amine would ordinarily be reduced.

Optionally, together with anhydrous ethyl or methyl alcohol there may bepresent in the fuel a proportion of an ether or ketone and where etheror a ketone is present in the fuel it will be usually found that theproportion of alcohol necessary to secure solution of the amine in aparticular hydrocarbon mineral oil may be diminished.

Further, the proportion of alcohol necessary will depend withincertaindimits upon the constitution and character of the hydrocarbonmano terial constituting the main or essential constituent of the fuel.v

In producing fuels in accordance with the invention in many cases itwill be found more convenient or profitable to employ, instead ofanhydrous alcohols in a substantially pure state, fuels which are atpresent on the market in Europe and which contain relatively largeproportions of anhydrous alcohol in association with hydrocarbons; aswell as certain of the fuels sold in other countries on a commercialscale and which are of the character above indicated.

Generally, the amine present in the fuel will be aniline or toluidine. V

While generally aromatic-amines properly so called will normally be usedin accordance with the invention, pyridine, methyl pyridine, or otherazocyclic hydrocarbons, may be employed; their use, however, is open toobjection if only on account of their unpleasant smell.

While the invention is mainly of value or advantage when applied to theproduction of fuels consisting essentially of petroleum hydrocarbonmaterial or containing large proportions of hydrocarbon materialsubstantially free from socalled aromatics, that is to say, hydrocarbonmaterials which are mainly or solely of a parafiinic or naphtheniccharacter and which, therefore, are poor solvents of aromatic amines,the invention is not to be regarded as limited to fuels the hydrocarbonconstituent of which consists wholly or mainly of material of thecharacter specified, as commercial or other considerations may render itdesirable to employ in the preparation of fuels in accordance with theinvention hydro-' carbon material containing a proportion of arcmatics.

The following particulars in accordance with the invention are given byway of example- To a petroleum hydrocarbon distillate having a suitableboiling range there is added aniline and 99.8 per cent. ethyl alcohol ina proportion adapted to yield a product containing 1.5 per cent. byvolume of the former and between 1 and 2 or 2 and 2.5 per cent. byvolume of the latter, such addition having the effect in certain casesof reducing knocking equivalent to the addition of a proportion of from25 to 35 per cent. of benzol.

If, instead of ethyl alcohol as such in the preparation of the fuel,consisting essentially of hydrocarbon material, alcohol and aniline,there is used a mixed fuel such as is at present marketed.

in Europe which contains a relatively large proportion of anhydrousalcohol to the mineral oil hydrocarbon distillate there may be addedaniline and a proportion of such a mixed fuel to yield a productcontaining the same in the respective proportions of 1.5 per cent. and 3to 5, for instance 4 to 4.5 per cent., by volume. 1

To a hydrocarbon distillate'possessing a suitable degree of volatilityfor use with existing carburetors for internal combustion engines andpoor in aromatics, aniline, acetone and substantially anhydrous ethylalcohol are added to yield a mixture containing, respectively, 1.5, 0.2and 0.8 per cent. by volume, the addition of aniline, acetone andsubstantially anhydrous ethyl alcohol in these proportions having theeffect of sup- "1 pressing knocking such as can be obtained by), theaddition of from 30 to 45 per cent. of benzol'fi,

If, instead of ethyl or methyl alcohol, a commercial fuel containingaliphatic hydrocarbons and an alcohol is employed with aniline andacetone the proportions of these ingredients should be, respectively, of1.5, 0.2 and 2 per cent. by volume.

Fuels in accordance with the invention do not 5 possess theobjectionable properties of fuels containing up to, for instance, 50 percent. of alcohol,

in that they do .not operate to cause the pistons, piston rings andcylinders to run dry nor do they cause pitting of the valves which isparticularly noticeable with fuels of high alcohol content operating athigh speeds for instance 4,000 revolutions per minute.

Fuels in accordance with the invention have, on the contrary, theadvantage of maintaining the pistons, piston chambers, and spark plugsclean, thus favourably influencing ignition and avoiding deposits ofcarbon and, further, they contain the amines in a perfect state ofdissolution even at very low temperatures.

Having now described my invention, what I claim as newv and desire tosecure by Letters Patent is:-.

1. A fuel for internal combustion engines consisting of petroleumhydrocarbon material of the character of gasoline together with a smallproportion of an aromatic amine and a small proportion of asubstantially anhydrous alcohol containing not more than two carbonatoms in its molecule.

2. A fuel for internal combustion engines consisting of petroleumhydrocarbon material of the character of gasoline together with a smallproportion of an aromatic amine and a small proportion of substantiallyanhydrous ethyl alcohol.

3. A fuel for internal combustion engines consisting of petroleumhydrocarbon material of the character of gasoline containing aproportion of an aromatic amine and a proportion of ethyl alcohol of atleast 99.5 per cent. strength within the limits of 1.2 to 1.5 parts foreach one part by volume of the aromatic amine present.

4. A fuel for internal combustion engines consisting of petroleumhydrocarbon material of the character of gasoline containing aproportion of an aromatic amine in the neighbourhood of 1.5

per cent. and a proportion of ethyl alcohol of at least 99.5 per cent.strength within the limits of 1.2 to 1.5 parts for each one part byvolume of the aromatic amine present.

5. A fuel for internal combustion engines consisting of petroleumhydrocarbon material of the character of gasoline together with a smallproportion of an aromatic amine, a small proportion of substantiallyanhydrous ethyl alcohol and a small proportion of acetone.

6. A fuel for internal combustion engines con-

